SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e56f00ac5bcb895f8fe9e444157c00780e24e15287b8e3f4bbc1b424a5d235c3' 
  AND token = '2uquAYqA9Z/bdhCDIzKHHDgUiMYeqnv9iQ9eJVj6Mfk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}